Ferguson, 33, submitted Lee, 25, with a triangle choke in the third round of their five-round bout at UFC 216 at T-Mobile Arena in Paradise, Nevada, adjacent to Las Vegas. It was Ferguson's 10th straight win, improving his overall MMA record to 25-3 and his UFC record to 13-1. Lee, of Detroit, "The Motown Phenom," fell to 16-3 (MMA) and 9-3 (UFC).

Immediately after the fight, Ferguson, who used to train at Knuckleheadz Boxing in Ventura but who now trains at his own facility in Big Bear, called out brash Irishman Conor McGregor, who captured the lightweight title last year.

"Defend or vacate," Ferguson pointedly told McGregor (who was not present) when interviewed in the octagon by UFC color commentator Joe Rogan.

Rather than defending his lightweight belt, McGregor took an extended leave from MMA to await the birth of his first child and to train for his much-hyped boxing match against Floyd Mayweather Jr. Mayweather TKO'd McGregor in the 10th round of their August bout, also at T-Mobile Arena.

The bout, however, hasn't been officially announced yet and in the wake of Ferguson capturing the interim lightweight belt, McGregor hasn't publicly said whether he wants to fight the Oxnard native next.

Ferguson paid his dues on the way to becoming the biggest-name mixed martial arts fighter to come out of Ventura County.

After knocking around the local fight circuit starting in 2008, Ferguson won the 13th season of the TV reality show, "The Ultimate Fighter," in 2011, and was awarded a six-figure contract with the UFC.

His fight against Lee was his first shot at a UFC belt. He was supposed to have fought for the interim lightweight title against Khabib Nurmagomedov at UFC 209 on March 4 at T-Mobile Arena, but the bout was canceled the day before when the Russian was taken to the hospital after falling ill while cutting weight. Nurmagomedov was later treated and discharged.

In a tweet following UFC 216, Nurmagomedov, a top lightweight contender, congratulated Ferguson for winning the interim lightweight belt.